As a dominant group of microzooplankton, the tintinnid ciliates (Ciliophora: Tintinnida) play a crucial role in aquatic ecosystems by linking the microbial food loop with the classical planktonic food web. However, taxonomic understanding has been greatly hindered by lorica polymorphism, combined with limited data on living cells and infraciliature, which in turn constrains progress in related fields such as ecology and physiology. In the present study, two freshwater tintinnids, namely Tintinnopsis wangi Nie, 1933, and T. tubuformis Chiang, 1956, collected from the Weishan Lake Basin, China, were redescribed based on living observation and protargol staining. Furthermore, the ciliary pattern of T. wangi is first reported, while that of another species corresponds well with its Shanghai population, indicating relatively high intraspecific stability of ciliary patterns in Tintinnida. In addition, based on the comparison of morphological characteristics, T. anhuiensis Nie, 1933, and T. sinensis Chiang, 1956, are considered synonyms of T. wangi. The characteristics of all species were compared with their original descriptions and further studies.
Fang et al. (Tue,) studied this question.